Conventional water purification involves waste water treatment by organic means. This is known to be biologically effective, and an activated sludge process is generally used.
However, in this activated sludge process, while sedimentation of solids is improved due to proliferation of filamentous fungus, generation of sludge is increased which leads to higher sludge treatment costs.
Furthermore in such processes, due to the amount of waste water, changes of load and inflow of toxic materials, an impact load phenomena occurs leading to considerable reduction in the treatment effect.
Conventionally, to find a solution to such problems, a trickling filter process, or rotating biological contactor process, etc, have been used to treat waste water, but all such processes had inconveniences such as breaking away of the microorganism, freezing during winter time and emission of odors.